1. Field of the Invention
The present invention relates to a backset adjustment structure of a dead bolt assembly provided to a door for locking the door which can adjust a backset distance to 60 mm or 70 mm in a convenient manner.
2. Discussion of Related Art
In order to provide a door lock to a door, an installation hole should be formed on the door, and a distance from the door's end to the installation hole's center is formed to one of two standards: 60 mm or 70 mm. Therefore, the dead bolt assembly has a backset adjustment structure, and according to a conventional structure disclosed in Utility Model Registration No. 83799 and Patent No. 104703 granted to the present applicant, a dead bolt and a bolt head are turned by about 45.degree. and pushed or pulled, and then 45.degree. turned to the original position for the backset adjustment. In another way, the screwy turning has been used for backset adjustment. However, these conventional structures are complicated to cause high production costs, and handling for backset adjustment is not easy and takes time thereby decreasing the yield in mass production. In addition, it is very hard for users to adjust the backset distance, thus requiring the more simple backset adjustment structure.